1. Field of the Invention
This invention pertains to a network storing method for a data processor having a function of efficiently storing, with a small memory capacity, data in a network structure such as an acoustic segment network, e.g., for use in a voice recognizer.
2. Description of the Related Art
Recently, an art of utilizing an acoustic segment network expressing a character string comprising words, e.g., in a pronunciation string has been developed for voice recognition and voice synthesis. Because such a data processor using a network has to store a very large number of networks, an efficient method for storing data in such a network using as little memory capacity as possible is sought after. In addition, a network storing method requiring the least number of accesses is also sought after, such that stored network data can be utilized as efficiently as possible.
FIGS. 1(a)-1(d) are explanatory charts of a conventional network data storing method.
In FIG. 1(a), an "N" indicates a node being a basic unit of data, and an "L" indicates a link specifying a connection between nodes.
A computer-based data, processor often uses data e.g., having a network structure shown in FIG. 1(a). Data in a network structure comprises node information about a node representing a basic unit of data and connection information regarding links between nodes and specifying their relationships.
Conventionally, data having a network structure such as the one shown in FIG. 1(a) are controlled in a memory format as shown in FIG. 1(b). That is, connection information is provided in correspondence with the node connection of each node "N". For instance, the fourth node "N", i.e., nodes "D", which is expressed by a "four [4] encircled", is connected to the second and third nodes "N" i.e., nodes "B" and "C", which are expressed by a "two [2] encircled" and a "three [3] encircled". Such data are stored in a matrix form. A part of the connection information having a value "0" shown in FIG. 1(b) indicates no further connection is available.
More specifically, as shown FIG. 1(c), node information specifying the content of node "N" is controlled for each node number N in a circle, and connection information specifying the previous node connection is provided for each node "N" corresponding to a particular node number N shown in FIG. 1(d).
A conventional method of storing a network structure controls information regarding to which previous node each node "N" is connected in a data structure having a matrix format shown in FIG. 1(b).
Such a conventional storing method for controlling each node "N" requires high memory capacity in a data storage region because a network storer must store a lot of parts in connection information having a value zero [0], which indicates no connection. This occurs because the number of connections of each node "N" is indefinite.
Also used is a method of storing the number of connections each node "N" has. However, such a method has a problem of wasting the regions for storing the number of connections each node "N" has.